Having been a waitress once (long, long ago!), I'll add that it always makes sense to let your server know your schedule. "We'd like to be finished with our meal by no later than....; don't worry about rushing us, we'd like to be sure we're out by....; if anything we order typically requires more time in the kitchen, please let us know; feel free to keep the meal paced pretty swiftly and drop the check as soon as possible...."
Giving the server the head's up, letting him/her know what kinds of ways you're willing to be flexible to meet your schedule, asking for the check at the point when you KNOW you're not going to order anything else -- do your part to help make it work out so that your server can do his/her part!